Dynamic test bench for aircraft system testing

ABSTRACT

An air to ground (ATG) communication system testing platform may be configured to operably couple a base station to an aircraft base radio in a lab environment. The testing platform may include a position simulator and a channel simulator. The position simulator may be configured to generate simulated aircraft position information and communicate the simulated aircraft position information to an aircraft base radio and a base band unit of the base station. The channel simulator may operably couple a remote radio head of the base station to the aircraft base radio, and may be configured to emulate channel conditions with respect to transmission of signaling generated by the remote radio head for communication to the aircraft base radio based on the emulated channel conditions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Application No. 63/020,171, filed May 5, 2020, which isexpressly incorporated by reference herein in its entirety.

TECHNICAL FIELD

Example embodiments generally relate to wireless communications and,more particularly, relate to a solution for the testing of aircraftcommunications systems prior to installation on the aircraft.

BACKGROUND

High speed data communications and the devices that enable suchcommunications have become ubiquitous in modern society. These devicesmake many users capable of maintaining nearly continuous connectivity tothe Internet and other communication networks. Although some of thesehigh speed data connections are available through telephone lines, cablemodems or other such devices that have a physical wired connection,wireless connections have revolutionized our ability to stay connectedwithout sacrificing mobility.

However, in spite of the familiarity that people have with remainingcontinuously connected to networks while on the ground, people generallyunderstand that easy and/or cheap connectivity will tend to stop once anaircraft is boarded. Aviation platforms have still not become easily andcheaply connected to communication networks, at least for the passengersonboard. Attempts to stay connected in the air are typically costly andhave bandwidth limitations or high latency problems. Moreover,passengers willing to deal with the expense and issues presented byaircraft communication capabilities are often limited to very specificcommunication modes that are supported by the rigid communicationarchitecture provided on the aircraft.

As improvements are made to network infrastructures to enable bettercommunications with in-flight receiving devices of various kinds, it isexpected that more solutions will be put in place to try to alleviatethe problems discussed above. These improvements may result in theprovision of new equipment on the aircraft. In a typical situation, inorder to confirm the performance of the new equipment, a test flightwould need to be performed. However, doing so is very expensive, andwould therefore preferably be avoided if possible.

BRIEF SUMMARY OF SOME EXAMPLES

In one example embodiment, an air to ground (ATG) communication systemtesting platform may be provided. The testing platform may be configuredto operably couple a base station to an aircraft base radio in a labenvironment. The testing platform may include a position simulator and achannel simulator. The position simulator may be configured to generatesimulated aircraft position information and communicate the simulatedaircraft position information to an aircraft base radio and a base bandunit of the base station. The channel simulator may operably couple aremote radio head of the base station to the aircraft base radio, andmay be configured to emulate channel conditions with respect totransmission of signaling generated by the remote radio head forcommunication to the aircraft base radio based on the emulated channelconditions.

In another example embodiment, a method of testing airborne and groundbased ATG communication equipment in a lab environment may be provided.The method may include operably coupling a base station to an aircraftbase radio via a testing platform, generating, via the testing platform,a simulated flight path, and simulating channel conditions associatedwith the simulated flight path, via the testing platform, to communicateinformation between the aircraft base radio and the base station basedon the simulated channel conditions.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 illustrates a functional block diagram of an ATG communicationnetwork that may benefit from employing an example embodiment;

FIG. 2 illustrates a block diagram of various components of a dynamicbench testing platform being employed in a lab context in accordancewith an example embodiment;

FIG. 3 illustrates a block diagram of the dynamic bench testing platformconfigured for handling a handover in accordance with an exampleembodiment;

FIG. 4 is a block diagram of the dynamic bench testing platform of anexample embodiment;

FIG. 5 illustrates a block diagram of a method of testing airborne andground based ATG communication equipment in a lab environment accordingto an example embodiment;

FIG. 6 illustrates a circuit diagram showing some example componentsthat may be used to implement the block diagram of FIG. 2 in accordancewith an example embodiment; and

FIG. 7 illustrates a circuit diagram showing some example componentsthat may be used to implement the block diagram of FIG. 3 in accordancewith an example embodiment.

DETAILED DESCRIPTION

Some example embodiments now will be described more fully hereinafterwith reference to the accompanying drawings, in which some, but not allexample embodiments are shown. Indeed, the examples described andpictured herein should not be construed as being limiting as to thescope, applicability or configuration of the present disclosure. Rather,these example embodiments are provided so that this disclosure willsatisfy applicable legal requirements. Like reference numerals may beused to refer to like elements throughout. Furthermore, as used herein,the term “or” is to be interpreted as a logical operator that results intrue whenever one or more of its operands are true.

As used in herein, the terms “component,” “module,” and the like areintended to include a computer-related entity, such as but not limitedto hardware, firmware, or a combination of hardware and software (i.e.,hardware being configured in a particular way by software being executedthereon). For example, a component or module may be, but is not limitedto being, a process running on a processor, a processor (or processors),an object, an executable, a thread of execution, and/or a computer. Byway of example, both an application running on a computing device and/orthe computing device can be a component or module. One or morecomponents or modules can reside within a process and/or thread ofexecution and a component/module may be localized on one computer and/ordistributed between two or more computers. In addition, these componentscan execute from various computer readable media having various datastructures stored thereon. The components may communicate by way oflocal and/or remote processes such as in accordance with a signal havingone or more data packets, such as data from one component/moduleinteracting with another component/module in a local system, distributedsystem, and/or across a network such as the Internet with other systemsby way of the signal. Each respective component/module may perform oneor more functions that will be described in greater detail herein.However, it should be appreciated that although this example isdescribed in terms of separate modules corresponding to variousfunctions performed, some examples may not necessarily utilize modulararchitectures for employment of the respective different functions.Thus, for example, code may be shared between different modules, or theprocessing circuitry itself may be configured to perform all of thefunctions described as being associated with the components/modulesdescribed herein. Furthermore, in the context of this disclosure, theterm “module” should not be understood as a nonce word to identify anygeneric means for performing functionalities of the respective modules.Instead, the term “module” should be understood to be a modularcomponent that is specifically configured in, or can be operably coupledto, the processing circuitry to modify the behavior and/or capability ofthe processing circuitry based on the hardware and/or software that isadded to or otherwise operably coupled to the processing circuitry toconfigure the processing circuitry accordingly.

Some example embodiments described herein provide strategies forimproved air-to-ground (ATG) wireless communication system performance.In this regard, some example embodiments may provide improved capabilityfor testing system components end-to-end without conducting a testflight. In this regard, example embodiments may provide a dynamic benchtesting platform (e.g., a “dynamic test bench”) that can be constructedin the lab, but provide full simulation of a radio access network (RAN)subsystem for testing of air-to-ground (ATG) broadband network servicesincorporating 4G, 5G or other long-term evolution (LTE) or futurenetwork technologies.

In general, ground based ATG RAN components, which provide the functionsand performance of LTE eNBs (evolved nodeBs), are operably coupled toaircraft-based ATG RAN components aboard the aircraft, which provide thefunctions and performance of LTE user equipment (UE). Meanwhile, an LTEevolved packet core (EPC) provides mobility management, authentication,authorization, and provides the functions of performance of the LTE EPC.Whereas the ground antenna (e.g., of the eNB) provides the capability oftransmitting and receiving radio frequency (RF) signals, other groundancillary equipment converts, regulates and distributes electrical powerfor the ground components and network interfaces to ground LNRs andnetwork backbone point of presence. The aircraft antenna provides thecapability to transmit and receive RF signals. Meanwhile, aircraftinterconnection cables provide the signal, power and groundinterconnections between the aircraft, aircraft base radio (ABR) and theaircraft antenna. The ground ATG RAN provides the digital, RF and analogprocessing functions of the LTE eNB.

The dynamic test bench is a high performance lab environment setup,which can be used for ATG network simulation. In this regard, thedynamic test bench provides a lab context in which full connectivity ofan ATG network can be simulated so that testing of ATG broadbandcommunication of network components can be provided. Performance andoperation of the ATG network (and specific components thereof) cantherefore be completed without needing to conduct test flights.Moreover, numerous scenarios can be tested with realistic conditionsbeing simulated accurately in order to ensure that the testing fullyconforms and translates to actual operating conditions when equipment isultimately deployed in the ATG network.

FIG. 1 illustrates a functional block diagram of an ATG network 100 thatmay benefit from employment of an example embodiment. As shown in FIG. 1, a first BS 102 and a second BS 104 may each be base stations of theATG network 100. The ATG network 100 may further include other BSs 106,and each of the BSs may be in communication with the ATG network 100 viaa gateway (GTW) device 110. The ATG network 100 may further be incommunication with a wide area network such as the Internet 120 or othercommunication networks. In some embodiments, the ATG network 100 mayinclude or otherwise be coupled to a packet-switched core network. Itshould also be understood that the first BS 102, the second BS 104 andany of the other BSs 106 may be either examples of base stationsemploying antennas configured to communicate via network frequencies andprotocols defined for the ATG network 100 with an aircraft 150.

The ATG network 100 may also be referred to as a core network. In someembodiments, the core network and all of the base stations of the ATGnetwork 100 (e.g., the first BS 102, the second BS 104 and the other BSs106) may combine with a wired transport network (e.g., including the GTWdevices 110 and other transport network components) to form a radioaccess network (RAN). Radio links between the RAN and communicationssystem equipment on the aircraft 150 may facilitate the ATGcommunications and define the coverage area of the ATG network 100. Asused herein, the term RAN refers to the deployed network providingcommunications (Radio Frequency) coverage to aircraft 150 whileinflight.

The aircraft 150 may be in-flight and may move between coverage areas(defined in 3D space above the surface of the earth) that are associatedwith respective ones of the first BS 102, the second BS 104 and otherBSs 106. These coverage areas may overlap such that continuous coveragecan be defined and the aircraft 150 can sequentially communicate withvarious ones of the BSs as the aircraft 150 travels via handovers. Insome cases, handovers of receivers on aircraft and/or various networkcontrol related functionalities may be accomplished under the control ofa network component such as a network controller.

The network controller could be located at one (i.e., centralized) ormore (i.e., distributed) locations within the ATG network 100. In somecases, the network controller or other components that are used by thenetwork controller may be located at one or more application servers 160that form a portion of, or are otherwise in communication with, the ATGnetwork 100. The network controller may include, for example, switchingfunctionality. Thus, for example, the network controller may beconfigured to handle routing calls to and from the aircraft 150 (or tocommunication equipment on the aircraft 150) and/or handle other data orcommunication transfers between the communication equipment on theaircraft 150 and the ATG network 100. In some embodiments, the networkcontroller may function to provide a connection to landline trunks whenthe communication equipment on the aircraft 150 is involved in a call.In addition, the network controller may be configured for controllingthe forwarding of messages and/or data to and from communicationequipment on the aircraft 150, and may also control the forwarding ofmessages for the base stations. The network controller may be coupled toa data network, such as a local area network (LAN), a metropolitan areanetwork (MAN), and/or a wide area network (WAN) (e.g., the Internet 120)and may be directly or indirectly coupled to the data network. In turn,devices such as processing elements (e.g., personal computers, laptopcomputers, smartphones, server computers or the like) can be coupled tothe communication equipment on the aircraft 150 via the Internet 120. Assuch, for example, the network controller may control the core networkby providing signaling and user data management and routing. The corenetwork may therefore act as the source of provisioned data for each ABRassociated with an aircraft and, as such, authenticates activated ABRsbased on secure unique ABR identifiers. The core network may alsofunction as the ingress/egress point for all end user traffic destinedto and received from network services, applications and the Internet120.

Although not every element of every possible embodiment of the ATGnetwork 100 is shown and described herein, it should be appreciated thatthe communication equipment on the aircraft 150 may be coupled to one ormore of any of a number of different networks through the ATG network100. In this regard, the network(s) can be capable of supportingcommunication in accordance with any one or more of a number offirst-generation (1G), second-generation (2G), third-generation (3G),fourth-generation (4G), fifth-generation (5G), long term evolution (LTE)and/or future mobile communication protocols or the like. In some cases,the communication supported may employ communication links defined usingunlicensed band frequencies such as 2.4 GHz or 5.8 GHz. Exampleembodiments may employ time division duplex (TDD), frequency divisionduplex (FDD), or any other suitable mechanisms for enabling two waycommunication (to and from the aircraft 150) within the system.Moreover, in some cases, this communication may be accomplished, and oneor both of the links associated therewith may be formed, via narrowradio frequency beams that are formed or otherwise resolved by theantenna assemblies associated with the aircraft 150 and/or the basestations (102, 104, 106). As such, beamforming technology may be used todefine one or both of the uplink to the aircraft 150 and the downlinkfrom the aircraft 150.

In some embodiments, one or more instances of a beamforming controlmodule may be employed on wireless communication equipment at either orboth of the network side or the aircraft side in example embodiments.Thus, in some embodiments, the beamforming control module may beimplemented in a receiving station on the aircraft 150 (e.g., apassenger device or device associated with the aircraft's communicationsystem (e.g., a WiFi router) or the ABR). In some embodiments, thebeamforming control module may be implemented in the network controlleror at some other network side entity (e.g., at a remote radio head (RRH)of each of the base stations). The beamforming control module may beconfigured to utilize location information (e.g., indicative of arelative location of the aircraft 150 from one of the base stations) tosteer or form a narrow beam toward the target (e.g., the aircraft 150)from the transmitting entity (e.g., the first BS 102). The narrow beammay then reach the target (e.g., the aircraft 150) at an angle ofarrival (in 3D space) determined by the relative location.

As can be appreciated from FIG. 1 , for each instance of the aircraft150, the connection of the aircraft 150 to the ATG network 100 forwireless communication purposes may include an instance of the ABR 170.The ABR 170 may include the entire ATG communications system installedin the aircraft 150. The ABR 170 may include, but is not limited to, theaircraft radio, antennas and associated electronic and power cabling. Asreferred to herein, the ABR 170 (or the aircraft radio thereof) mayinclude multiple measurement, processing, control and communicationsfunctions including, but not limited to: radio frequency (RF)transmission and receive, cell site selection and handover, protocolsignaling and user data communications with the ground segments of theATG network 100 (similar to a cell-phone or end-user device in atraditional wireless network). The communication function of theaircraft radio may be collectively defined as the Aircraft UserEquipment or AUE. The aircraft radio may also include functions relatedto the measurement, logic and control required for antenna selection andantenna beam control where multiple directional antennas or antenna beamsteering (electrical and/or mechanical) is deployed as a part of theaircraft side of the ATG system. The aircraft radio also provides amechanical, electrical and communications protocol interface (orinterfaces) to networking equipment on the aircraft 150 including, butnot limited to wireless access points, on-board wired networks (e.g.Ethernet) and avionics networks (e.g. ARINC-429).

Provisioning, activation and authentication for new devices to a networkoccur as defined specifically by the network protocol being employed.Thus, for example embodiments employed in connection with wirelesscellular networks, or similar networks, the processes for provisioning,activation and authentication may be similar to those defined by theThird Generation Partnership Project (3GPP), or 4G or LTE standards forwireless cellular networks. Within such a framework, provisioning is aprocess and storage systems within the core network that retains (forreference) a list of authorized unique ABR identifiers that are allowedto access network services along with the services each ABR is entitledto as well as the Quality of Service (QoS) to be provided to the ABR170. A unique ABR identifier (and thus the associated ABR) may beactivated with the unique identifier that has been authorized forservice. Authentication is the process by which the core networkvalidates that an ABR attempting to obtain service from the network isvalidated. The process typically includes the establishment of a securelink between the ABR 170 and the core network, and confirmation by thecore network that the unique identifier associated with (shared by) theABR 170 is provisioned and activated on the network. Once authenticated,the ABR 170 is attached to the network and may pass signaling and userdata/access network services.

Referring still to FIG. 1 , the ABR 170 may function similarly totraditional cellular User Equipment (UE). Thus, in operation, as the ABR170 enters the coverage area of the ATG RAN, the ABR 170 may beconfigured to, based on location information (and depending upon thespecific protocol implemented), identify a candidate serving cell site(e.g., first BS 102 or second BS 104) that may be available. The ABR 170may make signal strength measures of the various available controlsignals from the first and second BSs 102 and 104 and may select thestrongest/best cell site to which it will “attach”. Where the ABR 170includes multiple directional antennas and/or antenna beam formingtechnology, this process will also include measurements of the bestdirectional antenna and/or determination of the best possible beam angle(and formation of that beam) to assure the strongest possible radio linkbetween the ABR 170 and the serving cell site amongst the first orsecond BSs 102 or 104.

Depending upon the specific protocol implementation, the “attach”procedure between the ABR 170 and the ATG network 100 may require theexchange of (typically) encrypted authentication data between the ABR170 and the core network. In general, each ABR is uniquely identifiableby the core network by a provisioning process that occurs before thefirst time an ABR attaches to the network. This process includes theentry, processing and storage of a secure unique identifier for each ABRthat authorizes the ABR to use the network services and may furtheridentify specific network services and QoS available to the ABR 170, asmentioned above. During an “attach” attempt, an encrypted and secureexchange of information (protocol specific) may occur in which the ABR170 and core network will exchange encryption information, establish asecure link, and the ABR 170 will then provide its uniquely identifyinginformation. Upon verification of this information against theprovisioning data stored within the core network (e.g., at theapplication server 160), the core network will then authenticate the ABR170 and allow the ABR 170 to complete the network attach process andbegin communications of user data (and other signaling data as may beassociated with such network functionality as cell site hand-off anddata routing). In this regard, the ABR 170 may be handed off betweenbeams or sectors of one base station (e.g., first BS 102) or betweenbeams/sectors of different base stations (e.g., from the first BS 102 tothe second BS 104 or one of the other BSs 106).

End users (end user equipment) on the aircraft 150 may communicate withapplications and services on the ground (or communicate with otheraircraft) by means of the ABR 170 and ATG network 100. Direct networkaccess for end users on the aircraft 150 may therefore be provided viathe ABR 170. Access to the ABR 170 may be provided to end users on theaircraft 150 via a wireless network access point (e.g. WiFi, cabinwireless access point (CWAP), hotspot, Bluetooth, and/or the like) orwired network (e.g. Ethernet, A429, and/or the like) to which the ABR170 is connected. The ABR 170 manipulates incoming/outgoing dataaccording to the employed air interface protocol and passes that data(receives data from) the RAN, which in turn send/receives that datato/from the core network. The core network will then route the data tothe appropriate service or application. For example, an end user on theaircraft 150 wishing to use an internet service via a laptop computermay wirelessly attach to a WiFi hotspot in the aircraft 150. The WiFihotspot may in turn be connected via Ethernet to the ABR 170. The ABR170 communicates that user data via the RAN to the core network, whichin turn routes the end user data to the appropriate location on theInternet 120.

As discussed above, before the ABR 170 and any equipment on the aircraft150 can operate on the ATG network 100, provisioning and activation ofthe ABR 170 must be accomplished. Meanwhile, the ATG network 100 istypically optimized for coverage for aircraft that are in-flight.Moreover, coverage provided by the ATG network 100 for assets on theground is typically either non-existent, insufficient, or at leasthighly non-representative of the coverage that can be expected whilein-flight. As such, testing and maintenance activities that assure oroptimize performance while on the ground is normally highly ineffective.Specifically, during installation of communications equipment to provideATG systems on an aircraft, there is limited or no ability to confirmthat the ABR systems have been successfully installed without a “testflight”. Additionally, without the appropriate ATG network 100 coverage,there is no (or limited ability) to assure the an ABR 170 isappropriately provisioned in the core network until the aircraft 150 isflown into network coverage and the ABR 170 is either authenticated(allowed to attach because the unit is appropriately provisioned andactivated) or denied access (not allowed to attach because the unit isnot provisioned and activated on the network). Accordingly, theconfirmation of correct/optimized installation of ATG-based ABRequipment, as well as confirmation of provisioning and activationrequire the “test flight” to be flown, and all of the attendant costsassociated therewith to be absorbed. While generally sufficient toachieve the goal, the cost of one or more test flights can besubstantial. Accordingly, it is desirable to mitigate these costs byproviding an appropriate test system located on the ground that may beused in lieu of (or in advance of) flying the aircraft into ATG coverageto confirm performance and provisioning.

In order to avoid the cost and complication of performing a test flight,example embodiments introduce a dynamic bench testing platform that canbe constructed in the lab, and that is configured to enable performancetesting of aircraft communications systems that are to be installed onthe aircraft 150 before such installation on the aircraft 150 (andtherefore with the ABR 170 remains on the ground). In this regard, thedynamic bench testing platform of example embodiments may be configuredto allow full performance testing and optimization of the ABR 170 andany components thereof while the aircraft 150 is on the ground. Toaccomplish this, the dynamic bench testing platform may be configured tosimulate free space propagation in a typical ATG environment completewith various levels of fading and signal loss that may be encounteredduring normal ATG network operations. Additionally, the potential forhigh amounts of Doppler effects that can accompany communications withhigh velocity aircraft traveling at altitude either toward or away froma base station must be modeled. As such, movement of the ABR 170 on asimulated aircraft must be capable of modeling, and the dynamic benchtesting platform must be further capable of having its simulated basestations conduct beam handovers both intra-site and inter-site.

An instance of the ABR 170, which includes one or more highly complexantennas used to fulfill the requirements of a demanding link budgetthat may be inherent in a communication link needed to effectivelyoperate in this context, may therefore be fully tested without a testflight (or with fewer test flights). Accordingly, the cost and timing ofconducting test flights may be reduced and several scenarios that mayotherwise be difficult to test on actual flights, may actually be tailormade in the lab. For example, long duration flight testing or testing inspecific weather conditions may be more easily tested in the lab than inthe air. The ability to capture realistic data and conduct debugging orother modifications to the system may therefore be greatly enhanced. Thedynamic bench testing platform may therefore be capable of confirmingappropriate network provisioning and activation by supportingauthentication of the ABR 170 and attachment of the ABR 170 to the corenetwork, as well as confirm the operation and performance of the ABR 170and base station (and/or network) components in various differentconditions and scenarios. Moreover, the portable test system may furtherbe configured to confirm end user access to applications and servicesprovided by the ATG network 100 and/or the Internet 120 via the ABR 170.

FIG. 2 illustrates a block diagram of various components of a dynamicbench testing platform 200 of an example embodiment. In some cases, thedynamic bench testing platform 200 may include all of the componentsshown in FIG. 2 . In other words, the system of components shown in FIG.2 may itself be considered to be the dynamic bench testing platform 200.However, since many of the components tested may actually be componentsthat can be (or may actually be) deployed independently or incombination within the system (or ATG network 100) of FIG. 1 , thedynamic bench testing platform 200 could alternatively be considered tobe only those components that are unique to the lab environment in whichthe dynamic bench testing platform 200 operates. Thus, the example ofFIG. 2 shows the dynamic bench testing platform 200 to include onlythose components that are unique to the lab environment associated withinstitution of the dynamic bench testing platform 200.

In this regard, the dynamic bench testing platform 200 of this exampleincludes a channel simulator 210 and a position simulator (e.g., globalpositioning system (GPS) simulator 220). The GPS simulator 220 may beconfigured to simulate aircraft maneuver at high elevations includingpitch, roll, yaw, speed, acceleration, etc. The channel simulator 210may be configured to emulate channel conditions and wirelessconnectivity in light of the location and maneuvering being performed bythe aircraft 150. As such, for example, the dynamic bench testingplatform 200 may be configured to provide a robust capability fordefining scenarios or test profiles that simulate both aircraft maneuverand network connectivity that would be achieved in correspondingsituations. The dynamic bench testing platform 200 may also include aradio frequency signal analyzer 230 operably coupled to the channelsimulator 210 to analyze the output of the channel simulator 210 (i.e.,the same output that is provided to the ABR 170) in order to evaluatethe inputs to the ABR 170. The radio frequency signal analyzer 230 maybe one of potentially multiple sensors disposed at various points withinthe system shown in FIG. 2 to gather information on or otherwise monitorperformance criteria. The performance criteria may include physical andnetwork layer measurements. In some cases, the performance criteria mayinclude throughput, quality of service, SNR, Doppler offset, and/or thelike, including combinations of these parameters and others.

As shown in FIG. 2 , the dynamic bench testing platform 200 mayeffectively sit between (and bridge the communication gap between)components that are normally land-side (e.g., ATG network 100components) and components that are air-side (e.g., the ABR 170 and acabin wireless access point (CWAP) interface 240). Thus, for example,the dynamic bench testing platform 200 may operably couple the ABR 170to the remote radio head (RRH) 250 of an eNB. The eNB, which may be anyof the BSs (i.e., 102, 104, and 106) of FIG. 1 , may also include an eNBbase band unit (BBU) 260. The eNB BBU 260 may be operably coupled to theEPC 270, which may in turn be operably coupled to one or moreapplication servers 280. As such, the dynamic bench testing platform 200of this example may replace the antenna(s) to which the RRH 250 wouldnormally be connected, and the antenna(s) to which the ABR 170 wouldnormally be connected.

The dynamic bench testing platform 200 may therefore enable thedebugging, testing and troubleshooting of both (or either) air-side andland-side equipment in a controlled environment with controlledvariables. In other words, the dynamic bench testing platform 200 mayenable the creation of a lab environment in which forward and reverselinks for broadband communication over a wireless ATG network can berigorously tested without actually taking the ABR 170 airborne. As such,system issues can be discovered and troubleshot either before flighttesting, or specific issues found during a flight test can be recreatedand debugged or troubleshot thereafter on the ground with very highfidelity.

In some cases, various examples of user equipment (UEs) may be placed incommunication with the CWAP interface 240 (e.g., via WiFi) to testthroughput all the way from the application server(s) 280. For example,a laptop, cell phone, tablet, or the like, or multiple instances of suchdevices in any combination, may be operably coupled to the CWAPinterface 240 in order to access the same or different servicesassociated with the application server(s) 280. Performance and/or userexperience may be determined from end to end through the system in thismanner. Moreover, in some cases, the UEs may gather user experience dataas described in International Patent Application No. PCT/US2020/018728,filed on Feb. 19, 2020, entitled Method and Apparatus for ProvidingNetwork Experience Testing, the entire contents of which are herebyincorporated by reference.

The structure shown in FIG. 2 may support simulation of a number ofdifferent scenarios that do not involve handover to another eNB. Forexample, validation of signal to noise ratio (SNR) vs. throughput ratemay be handled using the structure of FIG. 2 . In this regard, forexample, the GPS simulator 220 may define a flight path that does notresult in a handover, and the channel simulator 210 may cycle throughvarious channel conditions associated with the geometries the simulatedaircraft path presents, and various weather or other simulated impacts.The structure of FIG. 2 may also be used for verification of Dopplerperformance by simulating a flight path that generates various differentDoppler effects and measuring the performance of the system in responseto the various different Doppler effects. The structure of FIG. 2 mayalso be used for SNR based re-entry testing, minimal SNR attach testing,link budget verification, among other things.

In order to conduct testing that involves handovers to other eNBs, thestructure of FIG. 2 may be modified slightly, as shown in FIG. 3 . Inthis regard, for example, support of handover scenarios may involve theaddition of a second RRH 250′ and a corresponding second eNB BBU 260′(which may together form a second eNB). Although one instance of thechannel simulator 210 may, in some cases, accommodate both (or evenadditional) instances of the RRH 250 and the second RRH 250′, a secondchannel simulator 210′ may also be employed to correspond to eachrespective one of the instances of the RRH 250 and the second RRH 250′.It also may be necessary or desirable to add additional (i.e., third,fourth, etc.) eNBs (and corresponding RRHs and eNB BBUs) in othertesting (e.g., for intra, inter site handover testing) with or withoutadditional channel simulators. However, adding sites should be anelementary modification to the structure of FIG. 3 .

When additional sites are added, a call router 290 may be employed tohandle cell site selection and handover responsibilities incommunication with the ABR 170 and EPC 270. In this regard, for example,the GPS simulator 220 may simulate movement of the ABR 170 toward anedge of the coverage area of one of the sites (e.g., an eNB or BSs 102,104 and 106). The channel simulator 210 may simulate channel conditionsthat show weakening of the signal received from the eNB. The signalconditions and/or knowledge of location (and future location) of the ABR170 may then be used to coordinate a handover to the second eNB. Thesecond channel simulator 210′ may simulate improving channel conditionsas range decreases to the second site, and the handover may becompleted.

The structure of FIG. 3 may also be used in connection with beamformingverification and beam selection testing (e.g., testing each individualbeam within a sector of a site). Testing associated with sectortraversals and intra site handovers may also be handled using thestructure of FIG. 3 . Additionally, it may be possible to attachmultiple ABRs, each with corresponding flight paths and channelconditions in some cases. In an example embodiment, up to 30 aircraft(and corresponding ABRs) could be attached to a single base station atany given time.

FIG. 3 illustrates the architecture of the dynamic bench testingplatform 200 in accordance with an example embodiment. The dynamic benchtesting platform 200 may include processing circuitry 310 configured tocontrol the operation of various components or modules of the dynamicbench testing platform 200, and a user interface 320 to facilitate userinteraction with the processing circuitry 310. However, in some cases,some or even each of the components may have their own instances ofeither or both of the processing circuitry 320 and the user interface320.

The processing circuitry 310 may be configured to perform dataprocessing, control function execution and/or other processing andmanagement services according to an example embodiment of the presentinvention. In some embodiments, the processing circuitry 310 may beembodied as a chip or chip set. In other words, the processing circuitry310 may comprise one or more physical packages (e.g., chips) includingmaterials, components and/or wires on a structural assembly (e.g., abaseboard). The structural assembly may provide physical strength,conservation of size, and/or limitation of electrical interaction forcomponent circuitry included thereon. The processing circuitry 310 maytherefore, in some cases, be configured to implement an embodiment ofthe present invention on a single chip or as a single “system on achip.” As such, in some cases, a chip or chipset may constitute meansfor performing one or more operations for providing the functionalitiesdescribed herein.

In an example embodiment, the processing circuitry 310 may include oneor more instances of a processor 312 and memory 314 that may be incommunication with the user interface 320, and in some cases also adevice interface 330. As such, the processing circuitry 310 may beembodied as a circuit chip (e.g., an integrated circuit chip) configured(e.g., with hardware, software or a combination of hardware andsoftware) to perform operations described herein. However, in someembodiments, the processing circuitry 310 may be embodied as a portionof laptop or personal computer (PC), or multiple instances of the same.

The user interface 320 may be in communication with the processingcircuitry 310 to receive an indication of a user input at the userinterface 320 and/or to provide an audible, visual, mechanical or otheroutput to the user. As such, the user interface 320 may include, forexample, a display, a touchscreen interface, a keyboard, a mouse, amicrophone, a speaker, indicator lights, buttons or keys (e.g., functionbuttons), and/or other input/output mechanisms.

The device interface 330 (if included) may include one or more interfacemechanisms for enabling communication with other devices (e.g., modules,entities, and/or other components of the dynamic bench testing platform200, or in communication therewith). In some cases, the device interface330 may be any means such as a device or circuitry embodied in eitherhardware, or a combination of hardware and software that is configuredto receive and/or transmit data from/to modules, entities, and/or othercomponents of the dynamic bench testing platform 200 (or systemincluding the same) that are in communication with the processingcircuitry 310.

The processor 312 may be embodied in a number of different ways. Forexample, the processor 312 may be embodied as various processing meanssuch as one or more of a microprocessor or other processing element, acoprocessor, a controller or various other computing or processingdevices including integrated circuits such as, for example, an ASIC(application specific integrated circuit), an FPGA (field programmablegate array), or the like. In an example embodiment, the processor 312may be configured to execute instructions stored in the memory 314 orotherwise accessible to the processor 312. As such, whether configuredby hardware or by a combination of hardware and software, the processor312 may represent an entity (e.g., physically embodied in circuitry—inthe form of processing circuitry 310) capable of performing operationsaccording to embodiments of the present invention while configuredaccordingly. Thus, for example, when the processor 312 is embodied as anASIC, FPGA or the like, the processor 312 may be specifically configuredhardware for conducting the operations described herein. Alternatively,as another example, when the processor 312 is embodied as an executor ofsoftware instructions, the instructions may specifically configure theprocessor 312 to perform the operations described herein.

In an example embodiment, the processor 312 (or the processing circuitry310) may be embodied as, include or otherwise control the operation ofthe dynamic bench testing platform 200 based on inputs received by theprocessing circuitry 310 responsive to receipt of position informationassociated with various scenarios defined by the GPS simulator 220and/or channel condition information provided by the channel simulator210. As such, in some embodiments, the processor 312 (or the processingcircuitry 310) may be said to cause each of the operations described inconnection with the dynamic bench testing platform 200 in relation tosimulation of the air interface between air-side and land-sidecomponents of the ATG network 100 to undertake the correspondingfunctionalities relating to simulation and testing responsive toexecution of instructions or algorithms configuring the processor 312(or processing circuitry 310) accordingly. In particular, theinstructions may include instructions for defining and executing testsor testing procedures and recording performance data associated withsuch tests or testing procedures for debugging, troubleshooting and/orthe like as described herein.

In an exemplary embodiment, the memory 314 may include one or morenon-transitory memory devices such as, for example, volatile and/ornon-volatile memory that may be either fixed or removable. The memory314 may be configured to store information, data, applications,instructions or the like for enabling the processing circuitry 310 tocarry out various functions in accordance with exemplary embodiments ofthe present invention. For example, the memory 314 could be configuredto buffer input data for processing by the processor 312. Additionallyor alternatively, the memory 314 could be configured to storeinstructions for execution by the processor 312. As yet anotheralternative, the memory 314 may include one or more databases that maystore a variety of data sets defining scenarios and/or channelconditions. Among the contents of the memory 314, applications and/orinstructions may be stored for execution by the processor 312 in orderto carry out the functionality associated with each respectiveapplication/instruction. In some cases, the applications may includeinstructions for providing inputs to control testing of handovers,beamforming, throughput, and various other network performancecharacteristics as described herein.

In an example embodiment, the GPS simulator 220 may be a flightsimulation software suite such as a system tool kit (STK) configured tosimulate flight patterns the aircraft 150 may fly. In some cases, theGPS simulator 220 may include a Skydel Software-Defined GNSS Simulator(e.g., Skydel PC along with software defined radios). The GPS simulator220 may be configured to provide a GPS signal to the ABR 170 so that apriori calculations can be performed. The calculations may be used todetermine which eNBs or BSs will be candidates for an LTE (e.g.,wireless ATG) connection to the ABR 170. The GPS simulator 220 mayfurther be configured to provide a common, stable time base to the ABR170 and to the eNB (e.g., the RRHs 250/250′ and eNB BBUs 260/260′) sothat the minimum frequency or amount of training is required on the LTElink. In some cases, additional test instruments may be used for precisemeasurements of physical and network layer parameters that may bepresent during flight testing, and such measurements may be used toaugment or enhance the flight simulation capabilities of the GPSsimulator 220.

In an example embodiment, the channel simulator 210 may be embodiedchannel emulator such as the Spirent Vertex® Channel Emulator. However,other channel emulators could be employed in alternative embodiments.The channel simulator 210 may be a module configured to providesimulation of various RF signal perturbations that may be specific tothe ATG network 100. The channel simulator 210 may be configured tomodel Doppler effects, timing advance caused by long ranges (between theaircraft 150 and BSs 102, 104 or 106) associated with the ATG network100, RF signal losses that are proportional to antenna patternsassociated with the highly complex antennas employed on the aircraft 150and BSs 102, 104 or 106. The channel simulator 210 may also beconfigured to simulate flight dynamics of the aircraft 150 as theaircraft 150 experiences pitch, roll, and yaw in flight (as simulated bythe GPS simulator 220). Thus, any flight pattern that can be performedby the aircraft 150 may first be simulated by the GPS simulator 220, thesimulated flight pattern may then be provided to the channel simulator210 and automated software tools associated therewith may build a batchof time based data series to generate channel emulator activity of thechannel simulator 210.

In some cases, in addition to the radio frequency signal analyzer 230,other lab test equipment may be employed. For example, a signalgenerator, vector network analyzer, and various RF accessories such asfilters, duplexers, network switches, attenuators, splitters,directional couplers, loads and jumpers may be employed to facilitateconstruction of the dynamic bench testing platform 200. Moreover, asnoted above, multiple instances of processing circuitry 310 (orcomputers/laptops) may be employed and configured to performcorresponding specific tasks or functions. For example, an eNB KPI (keyperformance indicator) monitoring script, ping testing, iperf testing,etc., may be defined and run on the processing circuitry 310 (or anotherinstance thereof). As such, the processing circuitry 310 may monitor(via the radio frequency signal analyzer 230 and/or other sensors ormeasurement devices located at various points in the system) performancecriteria and output copies or reports of the same to the user interface320 or other output devices.

The dynamic bench testing platform 200 described herein provides channelemulation capabilities for modeling fading environments for freepathloss propagation and other RF factors along with positioninformation simulation to both the ABR 170 and the eNB BBU 260. Thus,the dynamic bench testing platform 200 provides a fully programmablesystem with test functions that can be implemented by executing softwareon the hardware of the dynamic bench testing platform 200. The dynamicbench testing platform 200 is capable of running a single test script orrunning a series of test scripts in an automated fashion, therebyproviding test setup guidance and test results via the user interface320. In some cases, test instruments may also be software defined, andmay be controlled, monitored and measured by the dynamic bench testingplatform 200. Thus, the dynamic bench testing platform 200 may providefull end-to-end validation of ATG network components including bothland-side and air-side components. Authentication and network access mayalso be provided (end-to-end) for provisioning services and enabling enduser access to ATG network services and the Internet. The dynamic benchtesting platform 200 can also be quickly modified to accommodate newtest procedures and new scenarios.

FIG. 5 is a block diagram of a method of testing airborne and groundbased ATG communication equipment in a lab environment (i.e., withoutactual test flights). The method may include operably coupling a basestation to an aircraft base radio via a testing platform at operation500. The method may further include generating, via the testingplatform, a simulated flight path at operation 510. The method may alsoinclude simulating channel conditions associated with the simulatedflight path, via the testing platform, to communicate informationbetween the aircraft base radio and the base station based on thesimulated channel conditions at operation 520. In some cases, the methodmay include further optional operations, some of which are shown indashed lines in FIG. 5 . In this regard, for example, the method mayfurther include employing a radio frequency signal analyzer to monitorperformance criteria associated with the communication of theinformation between the aircraft base radio and the base station atoperation 530. Alternatively or additionally, the method may includemonitoring performance criteria associated with a site handover, asector handover and/or associated with two way communication between oneor more application servers (communicatively coupled to the basestation) and user equipment (communicatively coupled to the aircraftbase radio) at operation 540.

In accordance with an example embodiment, an ATG communication systemtesting platform may be provided. The testing platform may be configuredto operably couple a base station to an aircraft base radio in a labenvironment. The testing platform may include a position simulator and achannel simulator. The position simulator may be configured to generatesimulated aircraft position information and communicate the simulatedaircraft position information to an aircraft base radio and a base bandunit of the base station. The channel simulator may operably couple aremote radio head of the base station to the aircraft base radio, andmay be configured to emulate channel conditions with respect totransmission of signaling generated by the remote radio head forcommunication to the aircraft base radio based on the emulated channelconditions.

In some embodiments, the system (and corresponding components thereof)may be configured to include additional features, optional features,and/or the features described above may be modified or augmented. Someexamples of modifications, optional features and augmentations aredescribed below. It should be appreciated that the modifications,optional features and augmentations may each be added alone, or they maybe added cumulatively in any desirable combination. In this regard, forexample, the testing platform may further include a radio frequencysignal analyzer operably coupled to an output of the channel simulator.In an example embodiment, the position simulator may be configured togenerate one or more flight paths comprising the simulated aircraftposition information, and the channel simulator may be configured toemulate the channel conditions corresponding to the one or more flightpaths. In some cases, the channel simulator may be configured to emulatethe channel conditions corresponding to pitch, roll and yaw for eachsimulated position of the aircraft relative to the base station atrespective positions along the one or more flight paths. In an exampleembodiment, the channel simulator may be configured to emulate Dopplereffect and timing advance for each simulated position of the aircraftrelative to the base station at respective positions along the one ormore flight paths. In some cases, the position simulator may be furtheroperably coupled to a second base station, and the one or more flightpaths may include at least one flight path corresponding to a sitehandover from the base station to the second base station. In an exampleembodiment, a second channel simulator may be operably coupled to thesecond base station and the aircraft base radio, and the testingplatform is configured to monitor performance criteria associated withthe site handover. In some cases, the testing platform may be configuredto monitor performance criteria associated with sector handover forsectors of the base station or the second base station. In an exampleembodiment, the testing platform may be further operably coupled to oneor more application servers via an evolved packet core, and operablycoupled to one or more instances of user equipment via the aircraft baseradio. The testing platform may be configured to monitor performancecriteria associated with two way communication between the one or moreapplication servers and the user equipment. In some cases, theperformance criteria may include throughput, quality of service, signalto noise ratio, and Doppler offset.

FIG. 6 illustrates a circuit diagram 600 showing some example componentsthat may be used to implement the block diagram of FIG. 2 . Meanwhile,FIG. 7 illustrates a circuit diagram 700 showing some example componentsthat may be used to implement the block diagram of FIG. 3 .

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Moreover, although the foregoing descriptions and the associateddrawings describe exemplary embodiments in the context of certainexemplary combinations of elements and/or functions, it should beappreciated that different combinations of elements and/or functions maybe provided by alternative embodiments without departing from the scopeof the appended claims. In this regard, for example, differentcombinations of elements and/or functions than those explicitlydescribed above are also contemplated as may be set forth in some of theappended claims. In cases where advantages, benefits or solutions toproblems are described herein, it should be appreciated that suchadvantages, benefits and/or solutions may be applicable to some exampleembodiments, but not necessarily all example embodiments. Thus, anyadvantages, benefits or solutions described herein should not be thoughtof as being critical, required or essential to all embodiments or tothat which is claimed herein. Although specific terms are employedherein, they are used in a generic and descriptive sense only and notfor purposes of limitation.

What is claimed is:
 1. An air to ground (ATG) communication systemtesting platform configured to operably couple a base station to anaircraft base radio in a lab environment, the testing platformcomprising: a position simulator configured to generate simulatedaircraft position information and communicate the simulated aircraftposition information to an aircraft base radio and a base band unit ofthe base station; and a channel simulator operably coupling a remoteradio head of the base station to the aircraft base radio, the channelsimulator being configured to emulate channel conditions with respect totransmission of signaling generated by the remote radio head forcommunication to the aircraft base radio based on the emulated channelconditions.
 2. The testing platform of claim 1, further comprising aradio frequency signal analyzer operably coupled to an output of thechannel simulator.
 3. The testing platform of claim 1, wherein theposition simulator is configured to generate one or more flight pathscomprising the simulated aircraft position information, and wherein thechannel simulator is configured to emulate the channel conditionscorresponding to the one or more flight paths.
 4. The testing platformof claim 3, wherein the channel simulator is configured to emulate thechannel conditions corresponding to pitch, roll and yaw for eachsimulated position of the aircraft relative to the base station atrespective positions along the one or more flight paths.
 5. The testingplatform of claim 3, wherein the channel simulator is configured toemulate Doppler effect and timing advance for each simulated position ofthe aircraft relative to the base station at respective positions alongthe one or more flight paths.
 6. The testing platform of claim 3,wherein the position simulator is further operably coupled to a secondbase station, and wherein the one or more flight paths include at leastone flight path corresponding to a site handover from the base stationto the second base station.
 7. The testing platform of claim 6, whereina second channel simulator is operably coupled to the second basestation and the aircraft base radio, and wherein the testing platform isconfigured to monitor performance criteria associated with the sitehandover.
 8. The testing platform of claim 7, wherein the testingplatform is configured to monitor performance criteria associated withsector handover for sectors of the base station or the second basestation.
 9. The testing platform of claim 3, wherein the testingplatform is further operably coupled to one or more application serversvia an evolved packet core, and operably coupled to one or moreinstances of user equipment via the aircraft base radio, and wherein thetesting platform is configured to monitor performance criteriaassociated with two way communication between the one or moreapplication servers and the user equipment.
 10. The testing platform ofclaim 9, wherein the performance criteria include throughput, quality ofservice, signal to noise ratio, and Doppler offset.
 11. A method oftesting airborne and ground based air-to-ground (ATG) communicationequipment, the method comprising: operably coupling a base station to anaircraft base radio via a testing platform; generating, via the testingplatform, a simulated flight path; and simulating channel conditionsassociated with the simulated flight path, via the testing platform, tocommunicate information between the aircraft base radio and the basestation based on the simulated channel conditions.
 12. The method ofclaim 11, further comprising employing a radio frequency signal analyzerto monitor performance criteria associated with the communication of theinformation between the aircraft base radio and the base station. 13.The method of claim 11, wherein generating the simulated flight pathcomprises generating one or more flight paths comprising a simulatedmovement of the aircraft base radio, and wherein simulating the channelconditions comprises emulating the channel conditions corresponding tothe one or more flight paths.
 14. The method of claim 13, whereinemulating the channel conditions comprises emulating the channelconditions corresponding to pitch, roll and yaw for the simulatedmovement of the aircraft base radio at respective positions along theone or more flight paths.
 15. The method of claim 3, wherein emulatingthe channel conditions comprises emulating Doppler effect and timingadvance for each simulated position of the simulated movement of theaircraft base radio at respective positions along the one or more flightpaths.
 16. The method of claim 13, wherein the testing platformcomprises a position simulator operably coupled to the base station anda second base station, and wherein the one or more flight paths includeat least one flight path corresponding to a site handover from the basestation to the second base station.
 17. The method of claim 6, wherein asecond channel simulator is operably coupled to the second base stationand the aircraft base radio, and wherein the method further comprisesmonitoring performance criteria associated with the site handover. 18.The method of claim 17, wherein the method further comprises monitoringperformance criteria associated with sector handover for sectors of thebase station or the second base station.
 19. The method of claim 13,wherein the testing platform is further operably coupled to one or moreapplication servers via an evolved packet core, and operably coupled toone or more instances of user equipment via the aircraft base radio, andwherein the method further comprises monitoring performance criteriaassociated with two way communication between the one or moreapplication servers and the user equipment.
 20. The method of claim 19,wherein the performance criteria include throughput, quality of service,signal to noise ratio, and Doppler offset.